Chapter 23: Infectious Diseases Affecting the Genitourinary System

23.1 The Genitourinary Tract and Its Defenses

A. Urinary tract: removes substances from the blood, regulates certain body

processes, and forms urine and transports it out of the body

1. Includes the kidneys, ureters, bladder, and urethra

2. Defenses

A) Flushing action of urine

B) Desquamation of the epithelial cells

C) Acidity of urine

D) Antibacterial proteins in urine

E) Secretory IgA

B. Genital system: reproduction , aka the reproductive system

1. Male reproductive system includes the testes, epididymis, vas deferens,

prostate gland, scrotum, and penis

A) Defenses: flushing action of urine

2. Female reproductive system includes the uterus, fallopian tubes, ovaries,

and vagina

A) Defenses vary over the lifetime of the woman

1) Childhood and after menopause: mucous is the major defense with

secretory IgA antibodies

2) During reproductive years: changes in pH

23.3 Urinary Tract Diseases Caused by Microorganisms

A. Urinary Tract Infections (UTIs)

1. Urine is a good growth medium for many microorganisms

2. Reduced urine flow or accidental introduction of bacteria into the bladder

can result in cystitis

3. If the infection also affects the kidneys it is called pyelonephritis

4. An infection only in the urethra is known as urethritis

B. Bacterial Cystitis

1. Common urinary infection that involves the inflammation of the

bladder

A) About 30% of all women develop cystitis at some time during their

life

2. Most urinary tract infections originate from normal intestinal flora such

as E. coli (80-90%), Staphylococcussaprophyticus,and Klebsiella &

Proteus sp.

3. Nosocomial urinary tract infections are commonly caused by

Pseudomonas, Serratia, and Enterococcus which commonly grow

on catheters

4. Characterized by a sudden onset of symptoms

A) Pain in the pubic area

B) Frequent urges to urinate even when the bladder is empty

C) Burning pain accompanying urination (dysuria)

D) Cloudy urine

E) Orange tinge to the urine (hematuria)

F) Fever and nausea

G) Back pain indicates kidneys may also be involved

C. Leptospirosis

A) Zoonotic disease affecting the kidneys

1) Can infect many animals both wild & domestic but rats, pigs,

raccoons, cattle, skunks, and opossums appear to be the primary

reservoirs

B) Causative agent is Leptospirainterrogans

1) Originates from the bloodstream rather than from the lower urinary

system

C) Two phases

1) Early (leptospiremic) phase

a) Sudden high fever, chills, headache, muscle aches, conjunctivitis,

and vomiting

2) Second (immune) phase

a) Milder fever, headache, Weil’s syndrome (kidney invasion, hepatic

disease, jaundice, anemia, and neurological disturbances)

D) Transmission is by contact with infected urine usually by consuming

contaminated food or water

23.4 Reproductive Tract Diseases Caused by Microorganisms

A. Vaginitis and Vaginosis

1. Inflammation of the vagina

A) Vaginal itching to some degree

B) Burning and sometimes a discharge occurs

C) Symptoms depend on the etiologic agent

1) Candida albicans

a) Vulvovaginal candidiasis is the second most common cause of vaginal symptoms which include: itching, burning, thick white

vaginal discharge, redness and swelling

b) A yeast that is part of the normal vaginal flora in 35% of women

c) Considered non-contagious and is usually not sexually

transmitted

2) Gardnerella species

a) Infection called vaginosis rather than vaginitis because

inflammation in the vagina does not occur

b) Is the most common cause of non–STD vaginal symptoms

c) Vaginal discharge with a pungent fishy odor, especially after sex

d) Itching is common

B. Three broad categories of sexually transmitted diseases

1. Discharge diseases

2. Ulcer diseases

3. Wart diseases

C. Discharge Diseases

1. Increase in fluid discharge in male and female reproductive tracts

2. Includes trichomoniasis, HIV, gonorrhea, and Chlamydia infection

A) Trichomoniasis

1) Causative agent is Trichomonas vaginalis

2) Asymptomatic infections in approximately 50% of females and

males

3) Symptoms include the production of a frothy, green or yellow

discharge

B) Gonorrhea (“clap”)

1) Caused by Neisseria gonorrheae – also known as the gonococcus

2) Number of reported cases has greatly reduced since the 1970s

(more than 1 million down to less than 350,000)

3) Men usually develop painful urination and a thick yellow discharge

from the penis

a) Can occasionally spread from the urethra to the prostate gland

and epididymis

4) Women tend to have less severe symptoms or are asymptomatic

and more likely to be unknowing carriers

a) Symptoms include a mucopurulent or bloody vaginal discharge

often accompanied by a UTI

b) 15-30% of untreated cases ascend beyond the vagina and cervix

to infect higher reproductive organs resulting in pelvic

inflammatory disease (PID)

i) Increases the risk for ectopic pregnancies

5) Inflammatory responses to infection can cause scarring which can

partially obstruct the urethra or cause sterility in both men and

women

6) N. gonorrhoeae can also cause other problems including proctitis

resulting from anal sex, pharyngitis & gingivitis resulting from oral

sex, and conjunctivitis in newborns of infected mothers

C) Chlamydial Infections

1) The causative agent is Chlamydiatrachomatis

2) 70-85% of females and 10-25% of males are asymptomatic

a) In males the bacteria causes urethritis, a gray-discharge from the

penis and painful testes

b) In women it results in cervicitis accompanied by white drainage,

abdominal pain, endometritis, and pelvic inflammatory disease

3) The bacteria enters through tiny nicks or breaks in the perigenital

skin or the mucus membranes

a) The surrounding lymph nodes may become infected causing

them to enlarge and harden

i) The nodes may then burst and heal resulting in scarring that

can inhibit functionality of surrounding structures

4) Babies born to mothers with infections can develop eye infections

and pneumonia

D. Genital Ulcer Diseases

1. Two common infectious conditions resulting in lesions on a person’s

genitals are syphilis and genital herpes

A) Having one of these diseases increases the chances of infection with

HIV because of the open lesions

2. Syphilis

A) Caused by the spirochete Treponemapallidum

B) Syphilis is often called the “great imitator” because it symptoms

resemble many other diseases

C) There are three stages of syphilis

1) Primary syphilis

a) A hard, usually painless,chancre forms at the site of inoculation

on the internal or external genitalia

b) Usually heals without treatment in 3-6 weeks but the disease is

still present

2) Secondary syphilis

a) Usually begins about 6 weeks after the chancre heals

b) Initial symptoms are fever, headache, and sore throat

c) These progress into infection of the lymph nodes and a rash

covering the whole body

d) Symptoms usually disappear in a few weeks

e) About 30% of infected individuals enter into a period of latency

following secondary syphilis

i)Can last for many, many years

3) Tertiary syphilis

a) If the patient enters the tertiary stage the complications are

serious

i) Cardiovascular syphilis results in the small arteries of the

heart becoming weak & rupturing causing heart failure

ii) Syphilitic tumors can form on the liver, skin, bone, and

cartilage

iii) Neurosyphilis can infect the brain, cranial nerves, and dorsal

root of the spinal cord

4) Syphilis that infects pregnant women can spread across the placenta

to involve the fetus = congenital syphilis

a) Symptoms can range from mild to extreme depending on when

exposure occurred

3. Genital Herpes

A) Caused by herpes simplex viruses (HSVs); usually HSV-2

B) Symptoms: groups of vesicles with itching, burning, or painful sensations and local lymph node enlargement

1) Many persons have no symptoms while others have frequent

recurrences (generally less severe than original outbreak)

C) The latent form of the virus establishes itself in the ganglia of sensory

neurons and cannot be cured

D) Transmission can occur in the absence of symptoms but the risk is

much higher when lesions are present

E) Drugs of choice are Acyclovir (Zovirax) and Valacyclovir (Valtrex)

F) In the neonate and fetus, HSV infections are very destructive and can

be fatal

E. Wart Diseases

1. Human papillomavirus (HPV)

A) Causative agents of genital warts

B) An individual can be infected with HPV without having warts,

however

2. Molluscum Contagiosum

A) Caused by a virus of the pox family

B) Can take the form of skin lesions similar to HPV (usually have

smooth instead of a rough surface)